Smart pixel lighting and display microcontroller

ABSTRACT

A light emitting assembly is described. In one embodiment, one or more light emitting diode (LED) devices and one or more microcontrollers are bonded to a same side of a substrate, with the one or more microcontrollers to switch and drive the one or more LED devices.

RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 15/908,499, filed Feb. 28, 2018, which is a continuation ofU.S. patent application Ser. No. 15/479,962, filed Apr. 5, 2017, nowU.S. Pat. No. 9,959,815, which is a continuation of U.S. patentapplication Ser. No. 14/830,486, filed Aug. 19, 2015, now U.S. Pat. No.9,626,908, which is a continuation of U.S. patent application Ser. No.13/717,634, filed on Dec. 17, 2012, now U.S. Pat. No. 9,153,171, whichis incorporated herein by reference.

BACKGROUND Field

The present invention relates to a light emitting diode (LED)microcontroller. More particularly, embodiments of the present inventionrelate to an LED microcontroller for use in display or lightingapplications.

Background Information

Flat panel displays utilizing LED devices are gaining popularity in awide range of electronic devices, from small, handheld electronicdevices to large outdoor displays. High-resolution LED displays, such asthose used in modern computer displays, smart phones and televisions,typically use an active matrix display structure. In an active matrixdisplay, active driving circuitry is attached to each pixel orsub-pixel, allowing precise voltage switching for the individual pixelsthat passive matrix displays lack. The precise voltage switching allowsfor improved image quality and response time in comparison to passivematrix displays. In conventional active matrix displays, the switchingcircuitry at each pixel is implemented using a thin-film transistor(TFT) backplane driving the emissive elements. A typical TFT switchingcircuit used in emissive active matrix displays is the 2T1C circuit,which contains two transistors and one capacitor, although more advancedTFT circuits is possible.

The use of the TFT backplane allows improved precision in relation topassive matrix displays, however the use of the thin-film transistorbackplane is not without drawbacks. High quality TFT fabrication iscostly. The highest quality TFTs require fabrication on a quartzsubstrate due to the high temperatures involved in the fabricationprocess. Lower temperature processes can be used with a glass substrate,however the resulting transistors may suffer from low carrier mobility,reducing the conductivity of the transistors. Current leakage and powerconsumption can also become a problem, and uniformity issues can ariseat various points during the fabrication process.

SUMMARY OF THE DISCLOSURE

A smart-pixel microcontroller for controlling light emitting diodes isdescribed. The smart-pixel microcontroller can be used to replace theTFT backplane used in LED and LCD display technology, and can add newfunctionality not previously possible using thin film transistors asswitching and driving element in a display. In an embodiment a lightemitting assembly includes one or more light emitting diode (LED)devices and one ore more microcontroller to switch and drive the one ormore LED devices. The one ore more LED devices and the one or moremicrocontrollers are bonded to the same side of a substrate. In anembodiment, an LED device and microcontroller are bonded to thesubstrate with a material such as indium, gold, silver, copper, oralloys thereof.

In one embodiment, the smart-pixel integrated circuit is configured foranalog input, and has an input block and an output block containingelectronics. In such embodiment, the smart-pixel microcontroller iscontrolled with a voltage applied to scan lines and a data lines,similar to an active matrix display. In analog form, the smart-pixelmicrocontroller can accept at least one analog data input to control atleast one LED device, although multiple LED devices can be controlledwith a single microcontroller. In one embodiment, the smart-pixelmicrocontroller supplements analog circuitry with digital storage tofacilitate adaptive refresh rates and display self refresh. In oneembodiment, capacitive storage is used to storage analog input.

In one embodiment, the smart-pixel microcontroller is configured fordigital input, and has an input block and output block containingdigital logic, and a storage module with embedded memory. Digital inputcan come by way of a digital bus or point-to-point data link. MultipleLED devices or sensor devices can be controlled with a singlemicrocontroller. In one embodiment, adaptive display updates arefacilitated by data storage in each integrated circuit.

In one embodiment, a plurality of LED devices are bonded to the sameside of the substrate as the microcontroller, and are in electricalconnection with the microcontroller. The LED devices can be used assub-pixels in a display, and can be configured in a red, green, blue(RGB) sub-pixel arrangement. Other sub-pixel arrangements and schemesare also possible. In an embodiment, the light emitting assemblyincludes an array of LED devices and an array of microcontrollers bondedto the same side of the substrate. The number of microcontrollers in thearray of microcontrollers is less than the number of LED devices in thearray of LED devices. In an embodiment, each microcontroller is inelectrical connection with a plurality of pixels to drive a plurality ofLED devices in each pixel.

In addition to the controlling the emissive elements of the display, themicrocontroller can couple with one or more optical, electrical orthermal sensors. Alternatively the microcontroller may include one ormore sensors. In one embodiment, the smart-pixel microcontroller coupleswith one or more pressure sensors, which can be used to give visualdisplay feedback on a display when the display is touched, or totransmit user input in a touch display. In one embodiment, sensors canbe used to detect a drift in the white point of the display over time,and the display can be re-calibrated from time to time to maintain aconsistent white point.

One embodiment of a method of manufacturing a display or lighting deviceusing a receiving substrate, one or more transfer heads, and one or morecarrier substrates is also disclosed. The lighting or display device canbe manufactured by placing a micro scale sub-pixel array on a receivingsubstrate, where the receiving substrate is prepared with distributionlines to couple the components of the micro scale sub-pixel array. In anembodiment, a method of manufacturing a light emitting assembly includespositioning an array of transfer heads over a substrate carrying aplurality of LED devices, picking up the plurality of LED devices, andplacing the plurality of LED devices on a receiving substrate. Thisprocess may be repeated for a separate substrate carrying otherplurality of LED devices, for example, with different light emissioncharacteristics. The same or different array of transfer heads may beused. The same or different array of transfer heads are then positionedover a substrate carrying a plurality of microcontrollers, pick up theplurality of microcontrollers, and place the microcontrollers on thesame side of the receiving substrate as the plurality of LED devices. Inaccordance with embodiments of the invention the arrays of transferheads may operate in accordance with electrostatic principles. Theplurality of LED devices and microcontrollers may also be bonded to thereceiving substrate. In an embodiment, bonding is achieved by heatingthe plurality of LED devices and plurality of microcontrollers with therespective array of transfer heads. Bonding may also be achieved bythermocompression bonding with the array of transfer heads. Additionallyone or more sensor devices can also be placed on the receiving substrateusing an electrostatic transfer head.

The above summary does not include an exhaustive list of all aspects tobe discussed. It is contemplated that what is detailed below includesall systems and methods that can be practiced from all suitablecombinations of the various aspects summarized above.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated by way of example and not limitation in thefigures of the accompanying drawings, in which:

FIG. 1 is a circuit diagram of a smart-pixel micro-matrix in accordancewith one embodiment;

FIG. 2 is a block diagram of a smart-pixel microcontroller structure,according to one embodiment;

FIG. 3 is a block diagram of an alternate smart-pixel microcontrollerstructure, according to one embodiment;

FIG. 4 is a block diagram of a smart-pixel microcontroller input block,according to an embodiment;

FIG. 5A, 5B are a block diagrams of alternate of another smart-pixelinput blocks, according to an embodiment;

FIG. 6 is a block diagram of yet another smart-pixel input block,according to an embodiment;

FIG. 7 is a block diagram illustrating a smart-pixel output block,according to an embodiment;

FIG. 8 is a block diagram illustrating another smart-pixel output block,according to an embodiment;

FIG. 9 illustrates an exemplary smart-pixel display system according toan embodiment;

FIG. 10 is a timing diagram illustrating exemplary pixel update timingaccording to an embodiment;

FIG. 11 is a timing diagram of a smart-pixel frame update signal,according to an embodiment;

FIG. 12A, FIG. 12B, and FIG. 12C are block diagrams illustrating variousexemplary micro-matrix configurations, according to an embodiment;

FIG. 13 is a block diagram of an alternate smart-pixel microcontrollerstructure with sensor input, according to an embodiment;

FIG. 14 is a block diagram of an alternate smart-pixel microcontrollerstructure with a data relay, according to an embodiment;

FIG. 15 is a flow diagram of one method of creating a smart-pixelmicro-matrix display or lighting substrate, according to an embodiment;

FIG. 16 is an illustration processing micro-device substrates of microdevices into a receiving substrate, according to an embodiment; and

FIG. 17 is an illustration of a smart-pixel display assembly createdfrom an array of smart-pixels assembled on a display or lightingsubstrate, according to an embodiment.

DETAILED DESCRIPTION

Embodiments of the present invention provide a “smart-pixel”microcontroller for light emitting devices. The smart-pixelmicrocontroller utilizes the performance, efficiency, and reliability ofwafer-based microcontroller devices to replace the thin film electronicsused to form TFT backplanes. In one embodiment, one or morelight-emitting devices are coupled with the smart-pixel microcontrollerto create a smart-pixel light-emitting device. The emissive element ofthe smart-pixel light-emitting device can be one or more light emittingdiodes (LED) devices, one or more organic LED (OLED) devices, or one ormore micro-LED (μLED) devices. The absence of the TFT fabricationprocess allows the smart-pixel “micro-matrix” to be manufactured using arange of substrates, including rigid, semi-rigid, or flexiblesubstrates, glass substrates, plastic substrates, or any applicationsuitable substrate, as the substrate does not have to undergo a TFTfabrication process.

The smart-pixel device can be created by transferring one or more LEDdevices, and one or more smart-pixel microcontrollers onto a receivingsubstrate, which has been prepared with distribution lines to coupleeach smart-pixel microcontroller to its respective LED devices, othersmart pixel controllers, and/or external devices and circuits. Thesmart-pixel device can also include one or more sensors in addition to,or in place of one or more LED devices. The micro controller (μC), LEDdevices, and sensor devices are bonded to the same side of the substratesurface. Bonds can be made using various connections such as, but notlimited to, pins, conductive pads, conductive bumps, and conductiveballs. Metals, metal alloys, solders, conductive polymers, or conductiveoxides can be used as the conductive materials forming the pins, pads,bumps, or balls. In an embodiment, conductive contacts on the μC, LEDdevices, or optional sensor devices are thermocompression bonded toconductive pads on the substrate. In this manner, the bonds may functionas electrical connections to the μC, LED devices, or sensor devices. Inan embodiment, bonding includes alloy bonding the conductive contactswith the conductive pads. For example, the conductive contacts orconductive pads may include a material such as indium, gold, silver,tin, or copper for bonding. In an embodiment, when bonded together, theconductive contacts and conductive pads form an alloy such asindium-gold, tin-gold, tin-silver-copper. Other exemplary bondingmethods that may be utilized with embodiments of the invention include,but are not limited to, thermal bonding and thermosonic bonding. In anembodiment, the μC, LED devices, or sensor devices are bonded to landingpads in electrical connection with the distribution lines on thesubstrate to electrically couple one or more LED devices to thesmart-pixel μC. The receiving substrate can vary based on theapplication of the smart-pixel micro-matrix. In one embodiment, adisplay substrate is used, to form a smart-pixel micro-matrix LEDdisplay device, in which the smart-pixels are used as picture elementsin a high-resolution display.

In one embodiment, the smart-pixel micro-matrix is constructed on areceiving substrate suitable for use in lighting devices. Thesmart-pixel microcontrollers can be used to maintain precise brightness,uniformity, and color control over the emitted light. In one embodiment,the smart-pixel micro-matrix is used as an LED backlight, for liquidcrystal display (LCD) devices. Blue or UV LEDs in combination with ayellow, blue-yellow or white phosphor can be used to provide a whitebacklight for LCD displays. White light can also be generated by variouscombinations of single color LED devices with or without the use ofphosphors. In addition to white lighting, additional single color LEDdevices (e.g., red, amber, green, blue, etc.) devices can also be usedto provide a wider color gamut and color rendering index than otherwisepossible with white backlights.

One or more smart-pixel microcontrollers may also couple to form amicrocontroller network. A hierarchy of microcontrollers can be used,where a tiered arrangement exists between microcontrollers. Multipletypes of microcontrollers can be used for various applications, and themicrocontrollers can each be tied to a common data bus, coupled in adaisy chain, or may communicate wirelessly. The microcontroller networkcan enable fault tolerance, and can be used to determine the state ofthe smart-pixel micro-matrix.

In one embodiment, two-way communication is enabled between thesmart-pixel microcontrollers and other devices in the smart-pixelmicro-matrix. One or more sensors can couple with the smart-pixelmicrocontroller along with the emissive elements. The sensors can beambient light sensors, optical sensors, electrical sensors, or thermalsensors. In one embodiment, a pressure sensor is used, for example togive visual display feedback on a display when the display is touched,or to transmit user input in a touch display. In a smart-pixelmicro-matrix display, sensors can be used to detect a drift in the whitepoint of the display over time, and the display can be re-calibratedfrom time to time to maintain a consistent white point.

In one embodiment, a smart-pixel element is a micro scale device createdby the coupling of a micro scale sub-pixel controller (μC) device with amicro LED (μLED) device. The term “micro” in “micro scale, “micro LEDdevice,” “μLED device,” “μC device” and “micro scale pixel controller”all refer to the scale of 1 to 100 μm. For example, each μLED or each μCdevice may have a maximum (x, y) dimension of 1 to 100 μm. However, itis to be appreciated that the embodiments described herein may beapplicable to larger, and possibly smaller size scales, based on theapplication. In one embodiment micro scale sensor devices are used,along with pLED devices. Exemplary μLED devices and microchips that maybe utilized as micro-scale microcontroller devices in accordance withsome embodiments are described in U.S. patent application Ser. No.13/711,554. Though embodiments are not limited to such, and the μLEDdevices and microchips described in U.S. patent application Ser. No.13/711,554 are meant to be exemplary and not limiting. Such micro LEDdevices are highly efficient at light emission and may consume verylittle power (e.g., 250 mW for a 10 inch display) compared to 5-10 wattsfor LCD or OLED emission. In one embodiment, a smart-pixel is createdusing an OLED as the emissive component. In one embodiment, an inorganicLED is used as the emissive component of the smart-pixel. It should beappreciated, however, the smart-pixel micro scale microcontroller canalso couple with standard LEDs, and applications are not limitedspecifically to micro scale LEDs. In some embodiments the size of theμLED devices and a μC within a smart-pixel is determined by the size ofthe pixel pitch and resolution of a display. Exemplary displaydimensions are described in Table 1 below.

Various methods and configurations of the smart-pixel device aredescribed, including display, lighting, and backlighting configurationsin various size scales. However, certain embodiments may be practicedwithout one or more of the specific details disclosed, or in combinationwith other known methods and configurations. In order to provide athorough understanding, numerous specific details are set forth, such asspecific configurations, dimensions and processes. In some instances,well-known techniques and components have not been described inparticular detail, to avoid unnecessarily obscuring the discussion.

Throughout this specification, a reference to “one embodiment,” “anembodiment” or the like, indicates that a particular feature, structure,configuration, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention.Thus, the appearances of the phrase “in one embodiment,” “in anembodiment” or the like in various places throughout this specificationare not necessarily referring to the same embodiment of the invention.Furthermore, the particular features, structures, configurations, orcharacteristics may be combined in any suitable manner in one or moreembodiments.

The terms “over,” “to,” “between,” and “on” as used herein may refer toa relative position of one layer with respect to other layers. One layer“over,” or “on” another layer or bonded “to” another layer may bedirectly in contact with the other layer or may have one or moreintervening layers. One layer “between” layers may be directly incontact with the layers or may have one or more intervening layers.

The term “ON” as used in this specification in connection with a devicestate refers to an activated state of the device, and the term “OFF”refers to a de-activated state of the device. The term “ON” as usedherein in connection with a signal received by a device refers to asignal that activates the device, and the term “OFF” used in thisconnection refers to a signal that de-activates the device. A device maybe activated by a high voltage or a low voltage, depending on theunderlying electronics implementing the device. For example, a PMOStransistor device is activated by a low voltage while a NMOS transistordevice is activated by a high voltage. Thus, it should be understoodthat an “ON” voltage for a PMOS transistor device and a NMOS transistordevice correspond to opposite (low vs. high) voltage levels. It is alsoto be understood that where V_(dd) and V_(ss) is illustrated ordescribed, it can also indicate one or more V_(dd) and/or V_(ss). Forexample, a digital V_(dd) for can be used for data input, digital logic,memory devices, etc, while another V_(dd) is used for driving the LEDoutput block.

FIG. 1 is a circuit diagram of a smart-pixel micro matrix in accordancewith one embodiment. In one embodiment, the smart-pixel micro-matrix 100replaces the emissive element and the TFT layer of a conventional activematrix display with a micro-scale smart-pixel microcontroller (μC)integrated circuit device 110, to switch and drive one or more LEDdevices 115. In one embodiment, the smart-pixel micro matrix 100 ismanufactured on a receiving substrate, which has been prepared withdistribution lines 125 to couple the various μC devices 110 and the LEDdevices 115. In one embodiment, the distribution lines include scanlines, which are coupled to one or more scan drivers V_(select), anddata lines, which are coupled to one or more data drivers V_(data). Asillustrated, the LED devices 115 are coupled with a common ground, butmay each have a separate ground. In this figure, and in the figures tofollow, each illustrated LED device 115 may represent a single LEDdevice, or may represent multiple LED devices arranged in series, inparallel, or a combination of the two, such that that multiple LEDdevices may be driven from the same control signal. While the exemplarycircuit in FIG. 1 illustrates three control inputs and six LED outputs,embodiments are not so limited. A single μC 110 can control multiplepixels on a display, or multiple LED device 115 groupings for a lightingdevice. In one embodiment, a single μC 110 can control fifty to onehundred pixels.

In one embodiment, the μC device 110 couples with one or more red,green, and blue LED devices 115 that emit different colors of light. Ina red-green-blue (RGB) sub-pixel arrangement, each pixel includes threesub-pixels that emit red, green and blue lights, respectively. The RGBarrangement is exemplary and that embodiments are not so limited.Additional sub-pixel arrangements include, red-green-blue-yellow (RGBY),red-green-blue-yellow-cyan (RGBYC), or red-green-blue-white (RGBW), orother sub-pixel matrix schemes where the pixels may have a differentnumber of sub-pixels, such as the displays manufactured under thetrademark name PenTile®.

In one embodiment, the smart-pixel micro-matrix is used in LED lightingsolutions, or as an LED backlight for an LCD device. When used as alight source, blue or UV LEDs in combination with a yellow orblue-yellow phosphor may be used to provide a white backlight for LCDdisplays. In one embodiment, a smart-pixel micro-matrix using one ormore blue LED devices, such as an indium gallium nitride (InGaN) LEDdevice, is combined with the yellow luminescence from cerium dopedyttrium aluminum garnet (YAG:Ce³⁺) phosphor. In one embodiment, red,green, and blue phosphors are combined with anear-ultraviolet/ultraviolet (nUV/UV) InGaN LED device to produce whitelight. The phosphor can be bonded to the surface of the LED device, or aremote phosphor can be used. In addition to white light emission,additional red, green and/or blue LED device can also be used to providea wider color gamut than otherwise possible with white backlights.

FIG. 2 is a block diagram of a smart-pixel μC structure, according toone embodiment. In one embodiment, the smart-pixel μC device 110 has aninput block 215 and an output block 225. In one embodiment, thesmart-pixel μC device 110 has an additional data storage module 210,which can be an analog data storage module with one or more capacitors,or can be a digital data storage module consisting of static randomaccess memory (SRAM), dynamic random access memory (DRAM), ornonvolatile memory, such as flash memory. The input block 210 coupleswith input pins for power V_(dd) and ground V_(ss), as well as one ormore input pins V_(data(1)) through V_(data(n)). The smart-pixel μC 110is configurable to accept at least one input, which can control at leastone LED device, or at least one group of LED devices in series,parallel, or a combination of the two, such as one or more LED deviceswhich may be used in a white light source. In one embodiment, threeinput control signals control up to three LED devices (e.g., LED₁, LED₂,and LED₃) with red, green, and blue output, to create an RGB sub-pixelarrangement. In one embodiment, more than three LED devices can becontrolled, to allow sub-pixel arrangements such asred-green-blue-yellow (RGBY), red-green-blue-yellow-cyan (RGBYC), orred-green-blue-white (RGBW), or other sub-pixel schemes where the pixelsmay have a different number of sub-pixels. In one embodiment, thesmart-pixel μC 110 has a V_(select) input pin coupled with a scan driverinput, to provide a row select signal. In one embodiment, explicit rowselect input is omitted in favor of using a data update signal on thedata input.

In one embodiment, the output block 225 is configured to output currentto the various emissive devices coupled to the μC 110. In configurationsusing traditional analog driving techniques, the input voltage signalfrom the input data lines are converted to the appropriate current todrive each of the coupled sub-pixels. For example, a voltage input toV_(data(1)) can drive the LED₁ output in an LED lighting device. If theμC 110 input module has multiple inputs, such as V_(data(1)) throughV_(data(n)), the output block 225 can output up to n control lines fromLED₁ through LED_(n). One or more LEDs in series, parallel or acombination, can couple to the one or more LED outputs.

In one embodiment, the smart-pixel μC 110 has a data storage module 220,to store data values when input is received. The data storage module220, which may be an analog or digital storage module, stores the dataassociated with each display update. In one embodiment, the data storagemodule 220 contains one or more capacitors to store an incoming analogvoltage from an analog input block. In one embodiment, the data storagemodule 220 contains at least one cell of random access memory (RAM),such as static RAM (SRAM) or dynamic RAM (DRAM), to store a digitalvalue. In one embodiment, the data storage module 220 contains flashmemory. When the data storage module 220 is enabled, the smart-pixel μC110 stores the incoming data for each pixel and can continuously displaydata with minimal or no requirement for regular refreshing of staticdata. Instead, the pixel can continue to display the stored data untilthe display controller indicates an update event. Additionally, multipleframes of pixel data can be transmitted to the smart-pixel μC 110 in aburst manner and stored in the storage module 220. The smart-pixel μC110 can then cycle through the multiple frames at a specific updaterate, or based upon an update signal from the display controller.

FIG. 3 is a block diagram of an alternate smart-pixel μC, according toone embodiment. In one embodiment, the smart-pixel μC 310 has an inputblock 315, data storage module 320 and an output block 325. As in theanalog variant 110 shown in FIG. 2, the digital variant 310 has V_(dd)and V_(ss) voltage inputs, as well as an optional scan line or rowselect input V_(select) 205. In one embodiment, the output (e.g., LED₁through LED_(n)) of the digital smart-pixel μC 310 is coupled with oneor more LED devices in an LED lighting device, or in an LED backlight.In one embodiment, three or more LED devices can be controlled in ared-green-blue (RGB) sub-pixel arrangement, or some other sub-pixelmatrix, for use in a smart-pixel micro-matrix display device. Input isby way of a digital input 305, which can be a connection to a digitaldata bus, a digital data link, or a differential signaling interface.

In one embodiment, the data storage module 320 buffers input received bythe input block 315 for subsequent use by the output block 325. The datastorage module 320 can contain memory, such as DRAM, SRAM, or flashmemory, to buffer input data between refresh cycles. In one embodiment,all input data for a display frame is sent as a burst messageindividually to each smart-pixel μC 310, which store the pixel orsub-pixel information for the attached LEDs. The output module 325 canread the stored data and drive the attached LEDs at a standard updaterate, or a content dependent update rate.

FIG. 4 is a block diagram of a smart-pixel μC input block, according toone embodiment. In one embodiment, the input block 215 couples to a datainput 405 and a row select, or scan input 205. The input block 215 canutilize one or more variants of a sample and hold circuit 406. Theexemplary sample and hold circuit 406 has one transistor T1 402 and onecapacitor Cs 404, although more complex sample and hold circuits mayalso be used. The switching transistor 402 can be any type ofinsulated-gate field-effect transistor, such an n-type or a p-typesemiconductor transistor. In this configuration, the switchingtransistor T1 402 has a gate electrode coupled with the scan input 205,and a first source/drain electrode coupled with the data input 305, andsecond source/drain electrode coupled with the capacitor Cs. In oneembodiment, a voltage level scan signal enables the storage capacitor Cs404 to charge, which ultimately enables current flow to the LED devicescoupled with the output module. In one embodiment, the input module iscoupled with an output module containing a driving transistor. In suchembodiment, the μC creates a circuit similar to the 2T1C circuit of anactive matrix display, although additional circuit configurations arepossible. In one embodiment, the input module charges one or morecapacitors in the storage module 220. The storage module 220 can alsocontain digital storage, in place of, or in addition to the one or morecapacitors, and an analog-to-digital converter (ADC) 430 is used tostore a digital representation of the analog input.

FIG. 5A is a block diagram of a smart-pixel μC input block with ananalog data input coupled to digital storage. In one embodiment, theinput block 215 couples with a data input via a data input pin, andoutputs to a data storage module 320. In one embodiment, datasynchronization logic 520 detects an analog update signal on the dataline, and passes the incoming data into an ADC 530, to store a digitalrepresentation of the input data in the data storage module 320. In oneembodiment, the update signal is an indicator to the data sampling logicto update the pixel state value with a new value.

FIG. 5B is a block diagram of a smart-pixel μC input block with ananalog data input coupled to capacitive storage. In one embodiment, theinput block 215 couples with a data input via a data input pin, andoutputs an analog signal to a data storage module 220 using capacitivestorage. Data synchronization logic 520 detects an analog update signalon the data line 505, and passes the updated data into capacitivestorage 220.

FIG. 6 is a block diagram of an exemplary smart-pixel input block,according to one embodiment. The digital input block 315 is coupled withone or more digital input pins 305, and is coupled with a data storagemodule 220, which can contain capacitive storage, and/or one or morecells of digital memory, such as SRAM or DRAM, or nonvolatile memory,such as flash memory. An input receiver 540 couples with the digitalinput 305, and receives data from the one or more input pins and storesthe received data in the data storage module 220. In one embodiment, ascan line 205 is coupled with the input block, to enable a scan line tosignal a data update. In one embodiment, the data update events arecarried via the digital input.

FIG. 7 is a block diagram illustrating a smart-pixel output block,according to one embodiment. In one embodiment, the smart-pixel μCdevice 110 has an output block 225 configured to couple with an analoginput block, or capacitive storage. The output block 225 can use one ormore variants of a voltage to current conversion circuit 720 for eachLED output. The exemplary voltage to current conversion has a drivingtransistor T2 702, which has a first source/drain electrode coupled witha power source V_(dd), and a second source/drain electrode coupled withone or more LED devices. A storage capacitor Cs 704 coupled with thegate electrode of the driving transistor T2 702 can be included in avariant of the output block, or can be included in the input block(e.g., Cs 404 of FIG. 4), as part of connecting circuitry between theinput block 215 and the output block 225, or is one of the one or morecapacitors in the storage module 220. A first electrode of the storagecapacitor Cs 704 is coupled to a ground line V_(ss), or may have its ownground. A second electrode is coupled with the gate electrode of thedriving transistor T2 702. The voltage potential that is stored withinthe storage capacitor Cs opens the gate of the driving transistor T2702, to drive current to the one or more attached LED devices. Each LEDdevice (e.g., LED₁, LED₂, through LE_(n)) can represent a single LEDdevice, or one or more LED devices in parallel, series, or acombination. It is to be noted that the particular drive methodsemployed by the voltage to current converter 225 is for illustrationpurposes, and alternate LED driving circuits are within the scope of thevarious embodiments, and can vary based on whether the implementation isdisplay, lighting, or backlight oriented. FIG. 8 is a block diagramillustrating another smart-pixel output block, according to oneembodiment. In one embodiment, a smart-pixel output block 325 can readfrom digital memory in the data storage module 220, and has digitalcontrol logic 830 coupled with a digital-to-analog converter (DAC) 840.A serial data link from the digital control logic to the DAC can be usedto control one or more attached LEDs. It is to be noted that theparticular drive methods employed by the output block 325 is forillustration purposes, and alternate LED driving circuits are within thescope of the various embodiments, and can vary based on whether theimplementation is display, lighting, or backlight oriented.Additionally, each LED device (e.g., LED₁, LED₂, through LED_(n)) canrepresent a single LED device, or one or more LED devices in parallel,series, or a combination.

FIG. 9 illustrates an exemplary smart-pixel display system according toone embodiment. In this example, a display panel 920 has a mixed displaymode, in which a dynamic content 930, such as a video stream, is shownin a window, while the rest of the display shows static content 925,such as a page of text. Data input can couple with input pins of thesmart-pixel micro controller (μC) device 922. In one embodiment, anactivate/ignore signal 905 couples to a scan input, and is used totransmit address information, transmit frame update information, orframe metadata to the smart-pixel microcontroller. In one embodiment,both data and address information is transmitted over the data input910. The smart-pixel micro-matrix 920 can correspond to a singledisplay, or a portion of a display, such as a high definitiontelevision, or large outdoor display. In one embodiment, the μC device922 can couple to other microcontrollers via a microcontroller link 935.In one embodiment, the smart-pixel micro-matrix 920 can be one componentof a segmented or modular display created by coupling the μC device 922to an additional μC device with an attached smart-pixel micro-matrix.Coupling multiple smart-pixel micro matrix assemblies and linking eachμC device 922 can create increasingly larger displays using a modularconfiguration. In one embodiment, the microcontroller link 935 can be awireless link. In one embodiment, one or more μC devices can be used asrepeater devices in a microcontroller link 935 network.

FIG. 10 is a timing diagram illustrating exemplary pixel update timingaccording to one embodiment. In the example of FIG. 10, new data istransmitted whenever new content for a sub pixel controlled by oneembodiment of the smart-pixel μC device, such as the smart-pixel μCdevice 922 of FIG. 9. New data can be transmitted to the μC device 922and stored in a storage module. Each time new data is available for asub-pixel controlled by the μC device 922, data is transmitted, withoutfollowing a fixed schedule. A periodic refresh operation is notrequired, as shown in FIG. 10 by the horizontal lines, which indicateidle periods. In one embodiment, frame data is transmitted faster thanthe scheduled display update rate, and the pixel data is stored in oneembodiment of the μC device storage module (e.g., storage module 220,storage module 320). The pixel data is then read from the storage moduleat a scheduled update interval. This enables multiple frames of data tobe sent in a burst mode, received by an input block of the μC device922, and read from the storage module at the appropriate interval by theoutput block.

FIG. 11 is a timing diagram of a smart-pixel frame update signal,according to one embodiment. In one embodiment, an analog data inputV_(data(n)) senses voltages between a V_(dd) and a V_(ss) value. Forexample, V_(dd) can be +5V and V_(ss) can be −5V. Alternatively, V_(dd)is some positive or negative voltage and V_(ss) is tied to ground. Inmicro scale implementations, the voltages can be much smaller; inlighting or outdoor display implementations, the voltages can be higher.The analog voltage signal is sensed by data sync logic 420 coupled withan analog to digital converter (ADC). A digital sub-pixel data value isderived from the analog input voltage value. For example a drop toV_(ss) can act as a sync indicator 1110 to data sync logic (e.g., datasync logic 520). The data sync logic 520 can then pass incoming dataindicator 1120 to ADC circuitry 430, to store the analog input as adigital value in the data storage module 220. In one embodiment, theincoming data value is stored in data storage 220 in a capacitivestorage module.

FIG. 12A, FIG. 12B, and FIG. 12C are block diagrams illustrating variousexemplary micro-matrix configurations. FIG. 12A illustrates a smartpixel micro-matrix, which includes one or more smart-pixel μC devices1230, and a matrix of LED devices 1250, which can be conventional LEDdevices, organic LED devices, or μLED devices. Each μC device 1230 cancontrol a single LED, or a single μC device 1230 can control themicro-matrix 1240. In one embodiment, the micro-matrix is addressed inrow/column form. In one embodiment, each LED device 1250 is addressedindividually. In one embodiment, μLEDs are used to create a high-densityhigh definition display. In one embodiment, LED devices, as are known inthe art, are used for large outdoor displays, and one or more μC devices1230 can be networked to control the display, with various μC devices1230 acting as tile controllers for each segment of the display. In oneembodiment, each segment can communicate over a microcontroller link935, as illustrated in FIG. 9. In one embodiment, the micro-matrix 1240is an LED light source, to produce white or colored light, either by LEDemission, or via emission plus phosphorescence. In one embodiment, themicro-matrix 1240 is an LED backlight for an LCD display.

FIG. 12B illustrates an embodiment in which a μC device controls a meshof LED devices 1250 in a “passive” micro-matrix configuration, in whichthe LEDs are arranged in rows and columns. The LEDs can be coupled inseries, in parallel, or in a combination, to each LED output pin of theμC device 1230. One or more μC devices 1230 can be used as amicrocontroller for the LED devices.

FIG. 12C illustrates yet another LED to μC device arrangement accordingto one embodiment. Each LED device 1250 can be tied to a single outputpin of the smart-pixel μC device 1230. The LED devices 1250 can each beblue or UV LED devices used with a remote phosphor, to create whitelight. In one embodiment, the LEDs are blue LED devices using directlyapplied phosphor, such as a YAG:Ce3 phosphor. The LED devices 1250 canalso be part of a display device. The four LEDs illustrated can beconfigured as RGBY sub-pixels, or additional LED devices can be used,such as five LED devices to create a RGBYC arrangement.

FIG. 13 is a block diagram of an alternate smart-pixel μC, according toone embodiment. In one embodiment, a smart-pixel μC 1310 contains, oneor more embedded sensor devices 1302, such as an optical, electrical,thermal, or pressure sensor. The embedded sensors 1302 can couple with asensor data controller 1304. In one embodiment, the sensor datacontroller 1304 couples with one or more off chip sensors 1301, toreceive additional sensor data from off chip sensors 1301. In oneembodiment, sensor logic 1312, to process sensor data from embedded orexternal sensors is coupled with the sensor data controller 1304 and thedata storage 1320. Sensor data processed by the sensor logic 1312 can bestored in the data storage module 1320. In one embodiment, an externalcommunication module 1306 enables a microcontroller link 935 with otherμC devices, as illustrated in FIG. 9.

Some smart-pixel μC variants configured for sensor input can alsocontrol LED devices. In one embodiment, the smart-pixel μC 1310 has aninput block 1315, data storage module 1320 and an output block 1325. Inone embodiment, the smart-pixel μC 1310 has a digital input 305, similarto the digital input of smart-pixel μC 310 as shown in FIG. 3, as wellas V_(dd) and V_(ss) voltage inputs. In one embodiment, the output(e.g., LED₁ through LED_(n)) of the digital smart-pixel C 1310 iscoupled with one or more LED devices in an LED lighting device, or in anLED backlight. Each LED device output can couple with one or more LEDdevices in series, parallel, or a combination of series and parallel.

FIG. 14 is a block diagram of an alternate smart-pixel μC, according toone embodiment. In one embodiment, a smart-pixel C 1410 configured fordigital input has a data storage module 320 and an output block 325similar to the smart pixel μC 310 of FIG. 3, in addition to V_(dd) andV_(ss) voltage inputs. In one embodiment, the smart-pixel μC 1410additionally has an input block 1415 coupled with a relay output 1417,to relays or re-transmit incoming digital input 305 to one or moreadditional a smart-pixel μC. In one embodiment, the smart-pixel μC 1410drives output to one or more LED devices (e.g., LED₁ through LED_(n)).Each LED device output can couple with one or more LED devices inseries, parallel, or a combination of series and parallel.

FIG. 15 is a flow diagram of one method of creating a smart-pixeldisplay, according to one embodiment. An exemplary method ofmanufacturing micro scale devices, such as micro scale LED devices(μLEDs) and microchips, such as a micro integrated circuit controller(μC) are described in U.S. patent application Ser. No. 13/711,554, aspreviously incorporated. The μLED devices and μCs are prepared onseparate carrier substrates, and are poised for pickup and transferusing an array of electrostatic transfer heads. For example, an array ofred-emitting μLED devices, blue-emitting μLED devices, andgreen-emitting μLED devices are prepared separate carrier substrates.Likewise and array of μCs are prepared on a separate carrier substrate.As shown at block 1502, an array of electrostatic transfer heads ispositioned over a carrier substrate carrying a plurality of μLEDdevices, and picks up the plurality of μLED devices from the carriersubstrate. As shown at block 1504, the array of μLED devices is placedin the appropriate position on the receiving substrate. The same ordifferent array of electrostatic transfer heads is then used to pick up,transfer, and position each of the separate arrays of μLED devices foreach color used in the smart-pixel array onto the receiving substrate.The receiving substrate may be, but is not limited to, a displaysubstrate or a lighting substrate. As shown at block 1506, the same or adifferent electrostatic transfer head array is positioned over thecarrier substrate carrying an array of LED μController devices, andpicks up the array of μController devices from the μC carrier substrate.As shown at block 1508, each μC device is transferred onto the samereceiving substrate as the arrays of μLED devices and placed in theappropriate position on the receiving substrate. In one embodiment, oneor more sensor devices are also placed on the receiving substrate. Asshown at block 1510, the same or a different electrostatic transfer headarray as used for the μLED devices and μCs is positioned over thecarrier substrate carrying an array of μSensor devices, and picks up oneor more of μSensor devices from the μSensor carrier substrate. As shownat block 1512, each μSensor device is transferred onto the samereceiving substrate as the arrays of μLED devices and placed in theappropriate position on the receiving substrate.

FIG. 16 is an illustration processing micro-device substrates of microdevices into a receiving substrate, according to one embodiment.Separate carrier substrates are used for each μLED color 1610, for theμCs 1620, and for the μSensors 1625. One or more transfer assemblies1600 can be used to pick up and transfer microstructures from thecarrier substrates (e.g., 1610, 1620, 1625) to the receiving substrate,such as display or lighting substrate 1630, to form a smart-pixel array1615. In one embodiment, separate transfer assemblies 1600 are used totransfer any combination of μLED colors 1610, for the μCs 1620, and forthe μSensors 1625. The display substrate is prepared with distributionlines to connect the various the μLED and μC structures. Multipledistribution lines can be coupled to landing pads and an interconnectstructure, to electrically couple the μLED devices and the μC devices,and to couple the various μC devices to each other. The receivingsubstrate can be a display substrate 1630 of any size ranging from microdisplays to large area displays, or can be a lighting substrate, for LEDlighting, or for use as an LED backlight for an LCD display. The μLEDand μC structures are bonded to the same side of the substrate surface.

Bonds can be made using various connections such as, but not limited to,pins, conductive pads, conductive bumps, and conductive balls. Metals,metal alloys, solders, conductive polymers, or conductive oxides can beused as the conductive materials forming the pins, pads, bumps, orballs. In an embodiment, heat and/or pressure can be transferred fromthe array of transfer heads to facilitate bonding. In an embodiment,conductive contacts on the μC, LED devices, or optional sensor devicesare thermocompression bonded to conductive pads on the substrate. Inthis manner, the bonds may function as electrical connections to the μC,LED devices, or sensor devices. In an embodiment, bonding includesindium alloy bonding or gold alloy bonding the conductive contacts withthe conductive pads. Other exemplary bonding methods that may beutilized with embodiments of the invention include, but are not limitedto, thermal bonding and thermosonic bonding. In an embodiment, the μC,LED devices, or sensor devices are bonded to landing pads in electricalconnection with the distribution lines on the substrate to electricallycouple one or more LED devices to the smart-pixel μC. The receivingsubstrate can vary based on the application of the smart-pixelmicro-matrix. In one embodiment, a display substrate is used, to form asmart-pixel micro-matrix LED display device, in which the smart-pixelsare used as picture elements in a high-resolution display.

FIG. 17 is an illustration of a smart-pixel assembly created from anarray of smart-pixels assembled on a lighting or display substrate. Inone embodiment, the smart-pixel receiving substrate is a smart-pixelmicro-matrix 1730 that is prepared with distribution lines, to couplethe micro-matrix of μC devices and LEDs to one or more controllers. TheLED smart-pixel micro-matrix can be placed on the prepared substrate1730 in the manner described in FIG. 16. In one embodiment, thereceiving substrate 1735 is a display substrate, and multiplesmart-pixel micro-matrix assemblies can couple with each other to form ahigh-resolution display system. In one embodiment, the receivingsubstrate 1735 is a lighting substrate, and one or more smart pixelmicro matrix assemblies can be used with a yellow phosphor to form awhite light source. In one embodiment, one or more sensors, which can besensors as known in the art, or can be micro-scale sensors with amaximum (x, y) dimension of 1 to 100 μm, can be used to detect a driftin the white point of the display over time, and the display can bere-calibrated from time to time to maintain a consistent white point.

An optional sealant 1740 can be used to secure and protect thesubstrate. In one embodiment, the sealant is transparent, to allow adisplay or lighting substrate with top emission LED devices to displaythrough the sealant. In one embedment, the sealant is opaque, for usewith bottom emission LED devices. In one embodiment, a data driver 1710and a scan driver 1720 couple with multiple data and scan lines on thedisplay substrate. In one embodiment, each of the smart-pixel devicescouple with a refresh and timing controller 1724. The refresh and timingcontroller 1724 can address each LED device individually, to enableasynchronous or adaptively synchronous display updates. In oneembodiment, a brightness controller 1726 can couple with themicro-matrix substrate 1735 used to control the brightness of an LEDmicro-matrix LED lighting device, which can also be used as a backlightin an LCD. The brightness controller 1726 can also couple with one ormore optical sensors to allow adaptive adjustment of the light output.In one embodiment, one or more thermal sensors enable a smart-pixelbased LED light source to automatically manage thermal output.

Table 1 provides a list of exemplary implementations in accordance withthe various embodiments that use red-green-blue (RGB) displays with1920×1080p and 2560×1600 resolutions. It is to be appreciated thatembodiments of the invention are not limited to RGB color schemes or the1920×1080p or 2560×1600 resolutions, and that the specific resolutionand RGB color scheme is for illustrational purposes only.

TABLE 1 Display Pixel Pitch Sub-Pixel pitch Pixels per inch Substrate(x, y) (x, y) (PPI) 55″ (634 μm, 634 μm) (211 μm, 634 μm) 40 1920 × 108010″ (85 μm, 85 μm) (28 μm, 85 μm) 299 2560 × 1600  4″ (78 μm, 78 μm) (26μm, 78 μm) 326  640 × 1136  5″ (58 μm, 58 μm) (19 μm, 58 μm) 440 1920 ×1080

In the above exemplary embodiments, the 40 PPI pixel density maycorrespond to a 55 inch 1920×1080p resolution television, and the 326and 440 PPI pixel density may correspond to a handheld device withretina display. In accordance with embodiments of the invention, themaximum (x,y) dimension of the μLED devices and the μC for a smart-pixel120 fit within the allotted pixel pitch, such as the exemplary allottedpixel pitches described above with regard to Table 1. For example, inone embodiment a 5″ RGB display with 440 PPI may include a red-emittingμLED device, green-emitting μLED device, and blue-emitting μLED device,each with maximum (x, y) dimension that fits within the corresponding(19 μm, 58 μm) sub-pixel pitch, and a μC device that fits within the (58μm, 58 μm) pixel pitch. For example, in one embodiment a 55″ RGB displaywith 40 PPI may include a red-emitting μLED device, green-emitting μLEDdevice, and blue-emitting μLED device, each with maximum (x, y)dimension that fits within the corresponding (211 μm, 634 μm) sub-pixelpitch, and a μC device that fits within the (634 μm, 634 μm) pixelpitch.

In utilizing the various aspects of this invention, it would becomeapparent to one skilled in the art that combinations or variations ofthe above smart-pixel embodiments are possible. Although the presentinvention has been described in language specific to structural featuresand/or methodological acts, it is to be understood that the inventiondefined in the appended claims is not necessarily limited to thespecific features or acts described. The specific features and actsdisclosed are instead to be understood as particularly gracefulimplementations of the claimed invention useful for illustrating thepresent invention.

What is claimed is:
 1. A light emitting assembly comprising: an array oflight emitting diode (LED) device and an array of microcontroller chipsarranged in an array of micro-matrices, each micro matrix including amatrix of light emitting diode (LED) devices electrically connected witha microcontroller chip; wherein each microcontroller chip includes afirst output pin that is electrically coupled with a first string of LEDdevices to drive the first string of LED devices, and a second outputpin that is electrically coupled with a second string of LED devices todrive the second string of LED devices; and distribution lines toelectrically connect the array of microcontroller chips and the array ofLED devices, wherein the distribution lines electrically connect aplurality of microcontroller chips of the array of microcontroller chipsto one another.
 2. The assembly of claim 1, further comprising one ormore column drivers electrically connected with the array ofmicrocontroller chips.
 3. The assembly of claim 2, further comprisingone or more row drivers electrically connected with the array ofmicrocontroller chips.
 4. The assembly of claim 1, wherein each LEDdevice in the array of LED devices has a maximum length or widthdimension of 1 to 100 μm.
 5. The assembly of claim 1, wherein each LEDdevice in the array of LED devices has a maximum length or widthdimension of 1 to 100 μm.
 6. The assembly of claim 5, wherein the arrayof LED devices is bonded to landing pads in electrical connection withthe distribution lines.
 7. The assembly of claim 1, wherein eachmicrocontroller chip in the array of microcontroller chips includes oneor more input circuits and at least one output circuit.
 8. The assemblyof claim 1, further comprising a timing controller coupled with one ormore column drivers, the timing controller operable to signal one ormore row drivers to cause a first row of a display panel to be notrefreshed in a current data frame and a second row of the display panelto be refreshed in the current data frame.
 9. The assembly of claim 1,further comprising a plurality of sensors, wherein each sensor isselected from the group consisting of an optical sensor, and electricalsensor, a thermal sensor, and a pressure sensor.
 10. The assembly ofclaim 9, wherein each sensor is not located within a microcontrollerchip of the array of microcontroller chips.
 11. The assembly of claim 1,wherein each microcontroller chip includes a data input terminal and ascan input terminal.
 12. The assembly of claim 11, wherein eachmicrocontroller chip includes a sample and hold circuit, an analog todigital converter, and a data storage module.
 13. The assembly of claim11, wherein each microcontroller chip includes a data synchronizationlogic, an analog to digital converter, and a data storage module. 14.The assembly of claim 1, wherein each microcontroller includes a digitalinput terminal.
 15. The assembly of claim 1, wherein eachmicrocontroller includes a plurality of digital input terminals.
 16. Theassembly of claim 15, wherein each microcontroller includes a Vdd inputand a Vss input.
 17. The assembly of claim 15, wherein each microcontroller chip includes an input receiver, a data storage module, adigital control logic, and a digital to analog controller.
 18. Theassembly of claim 15, wherein each LED device in the array of LEDdevices has a maximum length or width dimension of 1 to 100 μm.